[content]: Add CanExceedIdleDeadlineIfRequired function to RendererScheduler.

content/renderer/scheduler/renderer_scheduler.h

Index: content/renderer/scheduler/renderer_scheduler.h
diff --git a/content/renderer/scheduler/renderer_scheduler.h b/content/renderer/scheduler/renderer_scheduler.h
index 7d2c39e3a86d5379382a8bf6929026343eee5bb4..7167f9585e614d87d4a6c360def3cedba1f8f766 100644
--- a/content/renderer/scheduler/renderer_scheduler.h
+++ b/content/renderer/scheduler/renderer_scheduler.h
@@ -70,6 +70,16 @@ class CONTENT_EXPORT RendererScheduler {
   // Must be called from the main thread.
   virtual bool ShouldYieldForHighPriorityWork() = 0;
 
+  // Returns true if a currently running idle task could exceed its deadline
+  // without impacting user experience too much. This should only be used if
+  // there is a task which cannot be pre-empted and is likely to take longer
+  // than the largest expected idle task deadline. It should NOT be polled to
+  // check whether more work can be performed on the current idle task after
+  // its deadline has expired - post a new idle task for the continuation of the
+  // work in this case.
+  // Must be called from the main thread.
+  virtual bool CanExceedIdleDeadlineIfRequired() const = 0;
+
   // Adds or removes a task observer from the scheduler. The observer will be
   // notified before and after every executed task. These functions can only be
   // called on the main thread.